Dabigatran etexilate is a new type of thrombin inhibitors, is the prodrug of dabigatran, and it belongs to non-peptide thrombin inhibitors, and it is developed and manufactured by Boehringer Ingelheim. It was first approved by FDA in the year 2010 to use in the prevention of stroke and systemic embolism for patients with nonvalvular atrial fibrillation. At present, this indication has been approved in more than sixty countries around the world. Dabigatran etexilate will turn into dabigatran that has direct anticoagulant activity after being taken orally and through stomach and intestine absorption. Dabigatran binds to the specific binding site of the fibrin of thrombin, preventing fibrinogen from degradating into fibrin, thus preventing thrombosis. Dabigatran can be dissociated from fibrin-thrombin conjugate, and exhibits reversible anticoagulation effect.
The chemical name of dabigatran etexilate mesylate is: 3-[(2-{[4-(hexaoxycarbonylamino-imino-methyl)-phenylamino]-methyl}-1-methyl-1H-benzimidazole-5-carbonyl)-pyridine-2-yl-amino-]-ethyl propionate-mesylate.
The structural formula is as follows:

Patent document U.S. Pat. No. 7,932,273B2 discloses crystal form I, crystal form II and semihydrate of dabigatran etexilate mesylate; WO2012027543A1 discloses crystal form A, B, C, D, G, H and III of dabigatran etexilate mesylate; WO2012044595A1 discloses crystal form Ms2-A of dabigatran etexilate dimesylate; WO2011110876A1 discloses crystal form IV of dabigatran etexilate mesylate (1:1).
For drugs that present polymorphism, different crystal forms can have different physical chemical properties, including melting point, chemical stability, apparent solubility, dissolution rate, optical and mechanical properties etc., and these physical chemical properties directly determine whether a specific crystal form can formulate drugs, and they affect the quality of active pharmaceutical ingredients and formulations. Therefore, although some crystal forms of dabigatran etexilate have been disclosed in prior art, it is still necessary to develop new crystal forms with properties different from the known crystal forms and can be used in the formulations to meet the stringent requirements for preparing drugs.